Get access

Enhancement of Cellulolytic Enzyme Activity by Clustering Cellulose Binding Domains on Nanoscaffolds

Authors

  • Do-Myoung Kim,

    1. Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, Aoba 6–6-11, Aramaki, Aoba-ku, Sendai, 980–8579, Japan
    Search for more papers by this author
  • Mitsuo Umetsu,

    Corresponding author
    1. Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, Aoba 6–6-11, Aramaki, Aoba-ku, Sendai, 980–8579, Japan
    2. Center for Interdisciplinary Research, Tohoku University, Aoba 6–3, Aramaki, Aoba-ku, Sendai, 980–8578, Japan
    • Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, Aoba 6–6-11, Aramaki, Aoba-ku, Sendai, 980–8579, Japan.
    Search for more papers by this author
  • Kyo Takai,

    1. Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, Aoba 6–6-11, Aramaki, Aoba-ku, Sendai, 980–8579, Japan
    Search for more papers by this author
  • Takashi Matsuyama,

    1. Toyota Central R&D Lab, Yokomichi 41–1, Oaza Nagakute, Nagakute-cho, Aichi-gun, 480–1192, Japan
    Search for more papers by this author
  • Nobuhiro Ishida,

    1. Toyota Central R&D Lab, Yokomichi 41–1, Oaza Nagakute, Nagakute-cho, Aichi-gun, 480–1192, Japan
    Search for more papers by this author
  • Haruo Takahashi,

    1. Toyota Central R&D Lab, Yokomichi 41–1, Oaza Nagakute, Nagakute-cho, Aichi-gun, 480–1192, Japan
    Search for more papers by this author
  • Ryutaro Asano,

    1. Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, Aoba 6–6-11, Aramaki, Aoba-ku, Sendai, 980–8579, Japan
    Search for more papers by this author
  • Izumi Kumagai

    1. Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, Aoba 6–6-11, Aramaki, Aoba-ku, Sendai, 980–8579, Japan
    Search for more papers by this author

Abstract

Cellulose, one of the most abundant carbon resources, is degraded by cellulolytic enzymes called cellulases. Cellulases are generally modular proteins with independent catalytic and cellulose-binding domain (CBD) modules and, in some bacteria, catalytic modules are noncovalently assembled on a scaffold protein with CBD to form a giant protein complex called a cellulosome, which efficiently degrades water-insoluble hard materials. In this study, a catalytic module and CBD are independently prepared by recombinant means, and are heterogeneously clustered on streptavidin and on inorganic nanoparticles for the construction of artificial cellulosomes. Heteroclustering of the catalytic module with CBD results in significant improvements in the enzyme’s degradation activity for water-insoluble substrates. In particular, the increase of CBD valency in the cluster structure critically enhances the catalytic activity by improving the affinity for substrates, and clustering with multiple CBDs on CdSe nanoparticles generates a 7.2-fold increase in the production of reducing sugars relative to that of the native free enzyme. The multivalent design of substrate-binding domain on clustered cellulases is important for the construction of the artificial cellulosome, and the nanoparticles are an effective scaffold for increasing the valence of CBD in clustered cellulases. A new design is proposed for artificial cellulosomes with multiple CBDs on noncellulosome-derived scaffold structures.

Get access to the full text of this article

Ancillary